First the disclaimer: I'm a hardheaded realist (okay, a cynic) about UFOs, crop circles, and Mothmen. That said, wouldn't it be cool if there were aliens among us?

Here's a bit of information I found interesting: A recent study asked a range of people these two questions:

Are humans the most important species on Earth?

Is there intelligent life on other planets?

People who said "yes" to the first question were distinctly more likely to say "no" to the second. In short, their belief in extraterrestrial life was affected by their values and attitudes about themselves, quite apart from any evidence they may have seen. And I bet you would find something similar about people's belief in extraterrestrial spacecraft.
Which leads me to boldly name five factors that could explain why some of us believe in UFOs:

1. Loneliness. We don't want to be the only intelligent life form in the universe. (Cheer up: We're not that intelligent either.)

2. Insecurity. Earth's problems seem too huge for us pitiful humans to solve. We can only hope to be rescued by aliens from another planet whose civilization is "vastly superior to our own."

3. Paranoia. Even in good times, we feel uneasy. We need some way to explain our irrational anxiety. "Aliens are watching us" does the job nicely.

4. Suspicion. We feel out of the loop. We don't know what's going on. It must be a conspiracy, we think, because the authorities must know, and if so, why aren't they telling us?

5. Truth. Maybe there are aliens spying on us--that would be another way to account for all those sightings!

To sort out these factors, we need to clarify what we do know about the UFO phenomenon: Where do facts end and speculation begin

Posted by isaac_benear on August 12, 2007 at 11:41 am

Mars (planet), fourth planet in distance from the Sun in the solar system. Mars is of special scientific interest because of its similarities to Earth. It has an atmosphere with seasons and changing weather, and its surface shows evidence of ancient water and volcanoes. The length of its day and the tilt of its axis are similar to those of Earth. Mars takes about two years to circle the Sun at an average distance of 228 million km (141.7 million mi). The possibility of life on Mars, now or in the distant past, is one of the major questions in astronomy. More space probes have been sent to Mars than to any other planet. Mars is named for the Roman god of war. It is sometimes called the red planet because it appears fiery red in Earth’s night sky, the result of rusty, iron-oxide mineral dust that covers its surface.

Mars is a relatively small planet, with a diameter of about 6,794 km (4,222 mi) or about half the diameter of Earth. Mars has about one-tenth Earth’s mass. The force of gravity on the surface of Mars is about three-eighths of that on Earth. Mars has twice the diameter and twice the surface gravity of Earth’s Moon. The surface area of Mars is almost exactly the same as the surface area of the dry land on Earth. Mars is believed to be about the same age as Earth, having formed from the same spinning, condensing cloud of gas and dust that formed the Sun and the other planets about 4.6 billion years ago.

Mars has two moons, Phobos and Deimos, which are named after the sons of the Roman god Mars. These tiny bodies are heavily cratered, dark chunks of rock and may be asteroids captured by the gravitational pull of Mars. Phobos orbits Mars once in less than one Martian day, so it appears to rise in the west and set in the east, usually twice each day. Deimos has the more ordinary habit of rising in the east and setting in the west.
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Observation from Earth
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Mars appears as a fairly bright, red, starlike object in Earth’s night sky. Because of the relative movements of Earth and Mars around the Sun, Mars appears to move backward in the sky for a short time around opposition, which is the time when the two planets are closest. As Mars and Earth orbit the Sun, the distance between them varies from about 56 million km (about 35 million mi) at their closest approaches to about 375 million km (about 233 million mi) when the planets are on opposite sides of the Sun. This change in distance causes the apparent size of Mars to vary by more than a factor of 5 and its brightness to vary by a factor of 25. Because the orbit of Mars is elliptical and not circular, Earth and Mars approach each other more closely during some orbits than others. For example, in late August 2003 Earth and Mars passed closer to each other than at any time since 1924. The two planets will not get that close again until the year 2287.
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When Mars is viewed through a telescope, it looks like a reddish-orange disk. When Mars is close to Earth, an observer with a telescope can usually see white ice caps at the north and south poles of Mars. These polar caps grow and shrink throughout the Martian year, just as the polar caps of Earth do. The darker areas of Mars’s surface may look greenish to the telescope observer, but this is an optical illusion caused by the contrast in color between the dark patches and the redder, brighter areas. Scientists believe that the dark areas are regions of relatively unweathered dark rocks and sand, while the bright areas are regions with deposits of dusty, fine-grained oxidized iron minerals. Scientists now believe that the “canals” people observed on Mars during the 19th century are actually another optical illusion, caused by the mind’s tendency to draw connections between irregular patches in a fuzzy image.

The Hubble Space Telescope (HST) provides the clearest Earth-based views of Mars, and astronomers use it to study the composition of the surface and to monitor the weather on the planet. HST has provided detailed images of local and global dust storms, enormous spiral-shaped water ice cloud systems, and changes in the bright and dark surface markings that have occurred since the first detailed images were taken during the 1970s. The telescope also has enabled spectroscopic measurements that provide comprehensive information on atmospheric chemistry and on the nature and variability of ices and minerals on the surface. Using HST images and other data, astronomers have determined that the atmosphere of Mars is generally cooler and clearer when the planet is farther from the Sun and warmer and dustier when it is closer. There also appear to be longer-term trends in the Martian climate, but as is the case for Earth’s climate, scientists are only now beginning to untangle the complexities required to understand and perhaps one day even predict climate changes on Mars. Orbiting spacecraft around Mars furnish constant data about the planet. However, they orbit so close to the planet and are in a fixed orientation relative to the Sun that they cannot see features in the early morning or late afternoon parts of the Martian day. As a result, astronomers still need telescopes like the HST to study Mars, particularly its early morning and late afternoon cloud formations.
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Orbit and Rotation
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Mars orbits the Sun at an average distance of about 228 million km (141.7 million mi), or 1.524 astronomical units (AU). An AU is equal to the average distance between the Earth and the Sun, or about 150 million km (93 million mi). However, Mars’s orbit is more elliptical than Earth’s—its nearest point to the Sun (perihelion) is about 42 million km (26 million mi) closer than its farthest point (aphelion), compared with only a 5 million km (3 million mi) difference between perihelion and aphelion for Earth. Mars’s year, or the time it takes to revolve once around the Sun, is about two Earth years long (687 Earth days). Mars receives less than half the amount of sunlight Earth does and is much colder.

Mars is tilted on its axis by about 25° (Earth is tilted at 23.5°). This tilt gives Mars seasons similar to Earth’s seasons. The elliptical orbit of Mars, however, causes the planet to have seasons of unequal lengths. For example, the southern hemisphere’s summer on Mars is about 25 days shorter than the northern summer. The intensity of sunlight also changes substantially during the Martian year: solar heating during the southern summer, when Mars is closer to the Sun, is 40 percent more intense than in the northern summer. During the warmer spring and summer period in the southern hemisphere, great dust storms have sometimes been observed through telescopes as bright yellow clouds. Sometimes white clouds of water vapor are visible, especially during the northern summer when Mars is near its farthest point from the Sun and its thin atmosphere is the coldest.

Like Earth, Mars turns counterclockwise on its axis (from west to east) when seen from its north pole and orbits the Sun in a counterclockwise direction. It takes Mars 24 hours and 37 minutes to rotate once on its axis (its sidereal day). Its solar day (the time between when the Sun next crosses the noon point in the sky) is about 24 hours and 39 minutes—its orbital motion around the Sun adds two minutes to its rotation period. (Earth’s solar day (24 hours) is four minutes longer than its rotation period.) The Martian solar day is sometimes called a sol.
IV
The Interior of Mars
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The density of Mars is about 30 percent less than that of Earth (3.94 g/cm3 vs. 5.52 g/cm3). Based on spacecraft measurements of the Martian gravitational field, scientists believe that the planet’s interior consists of a crust, mantle, and core like Earth’s interior. While the relative sizes of these components are not known for certain, the planet’s lower density combined with spacecraft mapping of the structure of its gravity field suggest that the planet’s iron-rich core and mantle are a smaller fraction of its volume than in the case of Earth. Mars therefore probably has a relatively thick crust compared to Earth. Beneath the Tharsis bulge, an area of volcanic activity in the northern hemisphere, the crust may be as thick as 130 km (80 mi). But the crustal thickness appears to vary significantly. For example, beneath the landing site of the United States spacecraft Viking 2, it may be as thin as 15 km (9 mi).

The Martian core is probably much like Earth’s, consisting mostly of iron, with a small amount of nickel. If other light elements, particularly sulfur, exist there as well, the core may be larger than presently thought. From studying Earth’s magnetic field and core, scientists theorize that the motions of the liquid rock in Earth’s core generate its magnetic field. Mars does not have a significant magnetic field, so scientists believe that Mars’s core is probably solid. However, spacecraft data indicate that Mars probably did have a strong magnetic field early in its history, suggesting that the core of Mars may have been at least partially liquid at one time.

Tectonics on the Earth is dominated by the relative motions and collisions of a few dozen large, moving lithospheric plates. Earthlike plate tectonics does not appear to be active on Mars today. However, there is considerable debate over whether Mars may have had plate tectonics in the distant past, when the core may have been molten. Ancient magnetic field patterns preserved in the crust show some similarities to magnetic field patterns that arise from plate tectonic processes on Earth. Because Mars is so much smaller than Earth, however, its more rapid cooling and crustal thickening after formation may have favored the creation of a one-plate planet rather than Earthlike plate tectonics.

Heat that melted at least some of the Martian interior has sculpted parts of the planet’s surface. In some places molten rock broke through the crust to form volcanoes. In other places, large-scale motions of the partially molten mantle cracked the crust to form large rifts and canyon systems. Scientists do not know if the interior of Mars is still geologically active. No evidence for active volcanism or tectonic movement has been found on the planet. However, images from orbiting spacecraft suggest that some of the Tharsis volcanoes have been periodically active in the last 100 to 350 million years, and perhaps as recently as 2 million years ago. Smaller volcanic cones discovered around the north pole may have erupted as recently as 1 million years ago.

Additional details about the Martian interior may have to await a time when more sophisticated spacecraft or even astronauts bring instruments such as seismometers to the planet, providing information similar to that which scientists routinely obtain for Earth’s interior today.

Posted by isaac_benear on August 12, 2007 at 11:49 am

Astronomy, study of the universe and the celestial bodies, gas, and dust within it. Astronomy includes observations and theories about the solar system, the stars, the galaxies, and the general structure of space. Astronomy also includes cosmology, the study of the universe and its past and future. People who study astronomy are called astronomers, and they use a wide variety of methods to perform their research. These methods usually involve ideas of physics, so most astronomers are also astrophysicists, and the terms astronomer and astrophysicist are basically identical. Some areas of astronomy also use techniques of chemistry, geology, and biology.

Astronomy is the oldest science, dating back thousands of years to when primitive people noticed objects in the sky overhead and watched the way the objects moved. In ancient Egypt, the first appearance of certain stars each year marked the onset of the seasonal flood, an important event for agriculture. In 17th-century England, astronomy provided methods of keeping track of time that were especially useful for accurate navigation. Astronomy has a long tradition of practical results, such as our current understanding of the stars, day and night, the seasons, and the phases of the Moon. Much of today's research in astronomy does not address immediate practical problems. Instead, it involves basic research to satisfy our curiosity about the universe and the objects in it. One day such knowledge may well be of practical use to humans. See also History of Astronomy.

Astronomers use tools such as telescopes, cameras, spectrographs, and computers to analyze the light that astronomical objects emit. Amateur astronomers observe the sky as a hobby, while professional astronomers are paid for their research and usually work for large institutions such as colleges, universities, observatories, and government research institutes. Amateur astronomers make valuable observations, but are often limited by lack of access to the powerful and expensive equipment of professional astronomers.

A wide range of astronomical objects is accessible to amateur astronomers. Many solar system objects—such as planets, moons, and comets—are bright enough to be visible through binoculars and small telescopes. Small telescopes are also sufficient to reveal some of the beautiful detail in nebulas—clouds of gas and dust in our Milky Way Galaxy. Many amateur astronomers observe and photograph these objects. The increasing availability of sophisticated electronic instruments and computers over the past few decades has made powerful equipment more affordable and allowed amateur astronomers to expand their observations to much fainter objects. Amateur astronomers sometimes share their observations by posting their photographs on the World Wide Web, a network of information based on connections between computers.
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How Astronomers Work
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Professional astronomers usually have access to powerful telescopes, detectors, and computers. Most work in astronomy includes three parts, or phases. Astronomers first observe astronomical objects by guiding telescopes and instruments to collect the appropriate information. Astronomers then analyze the images and data. After the analysis, they compare their results with existing theories to determine whether their observations match with what theories predict, or whether the theories can be improved. Some astronomers work solely on observation and analysis, and some work solely on developing new theories.

Astronomy is such a broad topic that astronomers specialize in one or more parts of the field. For example, the study of the solar system is a different area of specialization than the study of stars. Astronomers who study our galaxy, the Milky Way, often use techniques different from those used by astronomers who study distant galaxies. Many planetary astronomers, such as scientists who study Mars, may have geology backgrounds and not consider themselves astronomers at all. Solar astronomers use different telescopes than nighttime astronomers use, because the Sun is so bright. Theoretical astronomers may never use telescopes at all. Instead, these astronomers use existing data or sometimes only previous theoretical results to develop and test theories. An increasing field of astronomy is computational astronomy, in which astronomers use computers to simulate astronomical events. Examples of events for which simulations are useful include the formation of the earliest galaxies of the universe or the explosion of a star to make a supernova.

Astronomers learn about astronomical objects by observing the energy they emit. These objects emit energy in the form of electromagnetic radiation. This radiation travels throughout the universe in the form of waves and can range from gamma rays, which have extremely short wavelengths, to visible light, to radio waves, which are very long. The entire range of these different wavelengths makes up the electromagnetic spectrum.

Astronomers gather different wavelengths of electromagnetic radiation depending on the objects that are being studied. The techniques of astronomy are often very different for studying different wavelengths. Conventional telescopes work only for visible light and the parts of the spectrum near visible light, such as the shortest infrared wavelengths and the longest ultraviolet wavelengths. Earth’s atmosphere complicates studies by absorbing many wavelengths of the electromagnetic spectrum. Gamma-ray astronomy, X-ray astronomy, infrared astronomy, ultraviolet astronomy, radio astronomy, visible-light astronomy, cosmic-ray astronomy, gravitational-wave astronomy, and neutrino astronomy all use different instruments and techniques.

Posted by Tudun on August 21, 2007 at 8:51 am

Hi!
It's very good :)
I heard the music somewhere, but Is don't know where. What is it?

Posted by Jangaly_x on September 5, 2007 at 8:45 am

Interesting, I felt it. It is a art. surely I will see it more and more.

Posted by pdpete on February 16, 2011 at 9:27 am

Really good video with a lot of great shots was a pleasure to watch,too bad it wasn't longer

Posted by Tibor on February 17, 2011 at 10:30 am

Brilliant compilation. Mother Earth, we all must appreciate, document, explore, learn, observe, protect and respect her. We have so much to learn! We must preserve her beauty, all aspects, for generations to come.

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